Driving-belt.



No. "141,900.1" 1 PATENTBD 0011-20, 1903. 0.1. BOOTH.

DRIVING BELT. `APPLICATION FILED AUG. 3l, 1903.

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{ FI,C.2 4 FIC3" Vlam ,E @L b M671 W/T/vf :fr 'Nn-wrok UNITED STATESPatented October 20,` 1903.

GEORGE JAMES BOOTH, GF ROGHDALE, ENGLAND.

DRIVING-BELT.

SPECIFICATION forming part of Letters Batent No. 741,998, dated October20, 1903.

Application filed August t1I 1903.` Serial No. 171,441. (No model.)

To all' whom it may con/cern.:

Be it known that I, GEORGE J AMES BOOTH,

a subject ofthe King of Great Britain and Ireland, residing at RailwayLeather Works, 5 Rochdale, i'n the county of Lancaster, England, haveinvented new and useful Improvements Applicable to Driving-Belts, ofwhich the following is a specilication.

My invention is applicable to such machinedriving belts as are composedof more than one ply or layer of leather or other suitable materialfastened together by means of screws, rivets, or otherwise at shortintervals throughout their length or a combination of two or more kindsof material or materialsthat is,`where such layers cannot be used to runloosely on each other-and it relates more especially to such belts asarey required to work around V-grooved pulleys of small diameter-such,for instance, as the belts with V-shaped edges which are used fordriving motor-bicycles and for like purposes.

The object of my invention is to relieve the internal strains which areset up under such" circumstances when a thick compound belt made of twoor more plies or layers runs round a pulley of small diameter, whichstrains not only tend to loosen the fasteuings by which the severallayers are held together and to generally disintegrate the belt, butalso occasion loss of tractive power, owing to the force which is wastedin bending a thick belt. Further, the existence of these strains isprejudicial to the grip7 of the belt on the pulley, and such grip canonly be obtained by working the belt so tight as to set up an unduestrain on the bearings, causing an unnecessary increase of wasteful wearand Aa corresponding additional waste of power.

Take, for example, a V-ed ged motor-bicycle belt usually made half aninch in thickness or depthand running round a small pulley of an innercurve of, say, three inches and a half. Now it is evident that as thebelt is half an inch thick or deep the curve of the outer surface mustbe one inch greater in diameter than the inner one-1I. e., four inchesand a half-and as the difference between the circumference of athree-and-a-half-inch circle and one of four and a half inches is aboutthree inches and one-eighth and as the contact of the belt with thepulley is about twofths of the circumference it isv clear that while thebelt is passing round that part of the circumference the difference inlength between the outer and inner curves of the belt must be two-iifthsof three inches and one-eighth or one inch and a quarter, and this in anaverage length of iive inches-that is, two-fifths of the averagecircumference--the 6o inner layer having to be compressed and the outerlayer stretched to a considerable degree, thus setting up severeinternal strains which more or less rapidly disintegrate and destroy thebelt and at the same time cause faulty driving.

1t is found by experiment that while there is some extension of theouter surface of the belt when passing round the pulley there is a muchgreater amount of buckling or crum 7o pling action in the under layer orlayers, and

iheuce a straining disintegrating motion is constantly going on in thebelt itself in less degree, but analogous to that produced by bendingand breaking a rod,.piece of wire, or the like.

The nature of my said invention and the manner in which the same is tobe performed or carried into practical eifect will be readily understoodon reference to the annexed sheet 8o of drawings, marked with letters ofreference corresponding with those in the following explanation thereof.

Figure 1 on the drawings is a side or edge View of a compounddriving-belt made according to my invention. Fig. 2 is a longitudinalsection, and Fig. 3 a transverse section, of the same. Fig. llis an edgeview illustrating the action of the belt in passing round a pulley ofsmall dimensions. 9o

This belt is shown as composed of only two layers, an outer one a and aninner one b and in view of the fact that in passing round a smallpulley, such as c, Fig. 4, a thick belt crumples upon the inner side amore than it stretches on the outer side I relieve the consequentinternal strains by placing between the two layers a and b distance orseparating pieces d at suitable intervals apart, leaving between themfree or open spaces c, in which icc the inner layer a can crumple up, asshown, so as to adj ust itself to the alteration of length requiredwithout resistance other than such as each layer itself presents. Thetwo layers a and b of the belt and the separating-pieces d may be madeof leather, woven fabric, or other suitable material or combination ofma.- terials, and the separate layers a and b, together with theseparating-pieces or distancepieces d, may be all united together bymeans of screws f, as shown, or by means of metal rivets, or by bothscrews and rivets, or by stitching or other suitable means of fasteningthe same together, and the said fastenings not having to withstand thesevere internal strains present in the ordinary belt can be usedlighter, so that the materials of which the compound belt is made willbe displaced in a less degree. I would also remark that, although I havefor the sake of illustration shown the compound belt formed of only twolayers, I reserve to myself the right to make the same with anyconvenient number of superposed layers, with interveningseparating-pieces, and of any convenient breadth, according to the useto which the compound belt is to -be applied, and although, as beforestated, when the belt is to be used in connection with V-grooved pulleysI make the same with suitable sloping edges, as shown at Fig. 3, so asto obtain a maximum side grip, I provto relieve the strains abovereferred to and to impart greater pliability to the belt, with thefollowing results: irst, better drivinggrip, and consequently less slip;second, less friction on the bearings and consequent economy of power;third, less stretch; fourth, longer life of the belt.

I claim as my invention- Compound driving-belts, comprisingsuperposedlayers of belt material, distance-pieces placed at suitable intervalsbetween such layers separating them from each other, and the wholeunited by suitable means of connection, passing through the differentlayers and through the separating or distance pieces and uniting themtogether into one flexible compound belt, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

GEORGE JAMES BOOTH. Witnesses:

JNO, HUGHES, J. ERNEST HUGHES.

